Identifying cystic fibrosis programs in the United States with disproportionately disadvantaged patient populations: Methodology and implications for care.

Introduction: Providing care to under-resourced patients places additional burdens on CF care teams, therefore it is important to identify programs that serve disproportionately disadvantaged populations.

Methods: Using the U.S. CF Foundation Patient Registry data (2015-2022), we linked residential ZIP codes to area-level measures of socioeconomic disadvantage (the Area Deprivation Index - ADI, the Social Vulnerability Index - SVI) and rurality. We supplemented area-level data with patient-level measures, particularly health insurance type. Values were averaged across each program to create a program-level proportion of patients defined as disadvantaged (by either SVI, ADI, or insurance) or rural. CF care programs in the U.S. were then ranked by the proportion of disadvantaged patients for each year.

Results: We analyzed data from 41,577 individuals during the 8-year period. In 2022, 48.8 % of CF patients received care in pediatric programs (N = 130), 46.4 % in adult programs (N = 117), and 4.8 % in affiliate programs (N = 35). About one-quarter of CF programs (23.8 %, n = 67) scored in the worst 20 % for one disadvantage measure, 12.1 % (n = 34) in the worst 20 % for two disadvantage measures, and only 2.5 % (n = 7) scored in the worst 20 % for all three measures of disadvantage. There were distinct regional patterns associated with each classification method.

Conclusion: We recommend a joint use of all measures (SVI, ADI, and health insurance), annual update of rankings, and separate pediatric vs adult classification to identify CF programs that care for disproportionately disadvantaged patients and to design new strategies to meet the care needs of these populations.